Latch operating mechanisms



y 1968 A. R. CARLSON ETAL 3,331,508

LATCH OPERATING MECHANISMS Filed Oct. 11, 1965 2 Sheets-Sheet l In Men-01 5 Hr'lzlulr R Car/son Rona/d L. DEQHQ ior'neys May 7, 1968 A. R. CARLSON ETAL 3,381,508

LATCH OPERATING MECHANISMS 2 Sheets-Sheet 1" Filed Oct. 11, 1965 inyanfors n O.& m r a d e D A w M In a 1n n r fiz forneys United States Patent 3,381,508 LATCH OPERATING MEEi-HANISMS Arthur R. Carlson, North Balwyu, Victoria, and Ronaid L. Dearie, Beaumaris, Victoria, Australia, assignors to Die Casters Proprietary Limited, Collingwood, Victoria, Australia Filed Oct. 11, 1965, Ser. No. 494,696 Claims priority, application Australia, Oct. 16, 1964i, 50,530/64 Claims. (Cl. 70-216) ABSTRACT OF THE DISCLUSURE A latch operating mechanism for a door latch having a laterally projecting latch operating shaft adapted to oscillate about its longitudinal axis to actuate said latch.

The present invention relates to a latch operating mechanism for a door latch having a laterally projecting latch operating shaft oscillatable about its longitudinal axis to actuate said latch, said operating mechanism including: a lockable operating handle; a lock incorporated in said lockable operating handle and having an outer cylinder, a locking barrel rotatably housed in said outer cylinder and a key-way formed in said locking barrel to receive a key for operating said locking barrel; an outer hollow coupling member fixed to the lockable operating handle and rotatable therewith; an inner coupling member axially connectable to the latch operating shaft for rotation therewith and mounted for axial rotation in the outer coupling member; a connecting aperture formed in the outer coupling member; a connecting pin located in the inner coupling member and engageable with the connecting aperture when advanced to effect connection between the coupling members but disengaged from said connecting aperture when retracted; a retracting spring urging said connecting pin towards its retracted position; actuating means operable by oscillation of the locking barrel to advance or retract the connecting pin into and out of engagement with said connecting aperture to effect unlocking and locking of said latch mechanism respectively.

For convenience such a latch operating mechanism may hereinafter be referred to as a latch mechanism of the kind indicated.

The latch generally has a tongue which may be spring influenced into an advanced position and when a door to which the latch is fitted is closed the tongue engages in a slot formed in a frame member of a door frame surrounding the door. The tongue is retractable into the latch to free the tongue from the slot by oscillating the latch operating shaft. Generally the latch operating shaft is of square shape in external cross section and is connected to two operating handles each at one end of said operating shaft. Thus when either operating handle is actuated the door may be opened.

With a latch operating mechanism of the kind indicated the key may be used to move the connecting pin to its retracting position thus disconnecting the lockable operating handle from the latch operating shaft and in effect locking the door by preventing operation of the latch from that side of the door on which the lockable operating handle is located.

Hitherto latch operating mechanism of the kind indicated has incorporated actuating means of relatively complex construction which is also relatively bulky.

The primary object of the present invention is to provide an improved latch operating mechanism of the kind indicated in which the actuating means is of improved and simplified construction.

Accordingly the present invention provides a latch 3,381,508- Patented May 7, 1968 operating mechanism of the kind indicated characterised in that said actuating means includes: an actuating member oscillatably mounted in the inner coupling member, said actuating member having a main body within the inner coupling member, an internal cam formed on said main body, said internal cam being provided with an advancing cam face and a retracting cam face, said connecting pin having an inner end which engages the internal cam so that when the inner end engages the advancing cam face the connecting pin is advanced and when the inner end engages the retracting cam face the connecting pin is retracted, said actuating member having an outer end portion on that end nearer said lockable operating handle, said locking barrel having an inner end portion located adjacent said outer end portion, an external cam with an external cam face formed on said outer end portion, a cam projection extending from said inner end portion, the relative arrangement of said cam projection and said external cam face being such that when the key-way is in a neutral position ready for insertion or withdrawal of said key the cam projection is incapable of engaging said external cam face during any relative rotational movement of said actuating member and said lockable operating handle whereas the key may be used to oscillate said locking barrel in either direction from said neutral position so that said cam projection oscillatably engages said external cam face whereby said latch mechanism may be locked by turning the locking barrel in one direction from its neutral position and unlocked by turning the locking barrel in the other direction from its neutral position.

In order to further describe the present invention reference is now made to the accompanying drawings in which:

FIGURE 1 shows a cross-sectional elevation of a latch operating mechanism according to the invention coupled with a latch;

FIGURE 2 is a cross-section of the latch operating mechanism of FIGURE 1 on the line II-II;

FIGURE 3 is an elevation from the left-hand side of FIGURE 1 showing the lockable operating handle;

FIGURE 4 is an exploded elevational view of the latch operating mechanism of FIGURE 1 with parts removed for clarity;

FIGURE 5 is a cross-section line VV of FIGURE 4; and

FIGURE 6 is a cross-section on the line VI-VI of FIGURE 1.

The description which follows mentions essential and optional features of the invention and uses reference numerals to refer to these features as illustrated in the form of a preferred embodiment shown in the drawings.

As hereinbefore mentioned latch operating mechanism to which the invention relates is operable with a latch 6 which has a laterally projecting latch operating shaft 7 which may be of square shape in external cross-section and is oscillatable about its longitudinal axis to actuate the latch 6.

Such latch operating mechanism includes a lockable operating handle 8; a lock 9 incorporated in said lockable operating handle and having an outer cylinder 11, a locking barrel 12 rotatably housed in said outer cylinder 11 and a key-way formed in said locking barrel 12 to receive a key 13 for operating said locking barrel 12; an outer hollow coupling member 14 fixed to the lockable operating handle 8 and rotatable therewith; an inner coupling member 16 axially connectable to the latch operating shaft 7 for rotation therewith and mounted for axial rotation in the outer coupling member 14; a connecting aperture 17 formed in the outer coupling member; a connecting pin 18 located in the inner coupling member 16 and on enlarged scale on the engageable with the connecting aperture 17 when advanced to effect connection between the coupling members but disengaged from said connecting aperture when retracted; a retracting spring 19 urging said connecting pin 18 towards its retracted position; actuating means operable by oscillation of the locking barrel 12 to advance or retract the connecting pin 18 into and out of engagement with said connecting aperture 17 to effect unlocking and locking of said latch mechanism 6 respectively.

According to the present invention the actuating means includes an actuating member 21 oscillatably mounted in the inner coupling member 16 and capable of oscillatable movement therein. The actuating member has a main body 22 within the inner coupling member, an internal cam 23 formed on the main body and provided with an advancing cam face 24 and a retracting cam face 26. The advancing and retracting cam faces are preferably at substantially right angles to each other and merge at a common edge 27.

The inner end 28 of the connecting pin engages the internal cam so that when in engagement with the advancing cam face 24 the connecting pin 18 is advanced and engages the connecting aperture 17 whereas when the connecting pin 13 engages the retracting cam face 26 the connecting pin 18 is retracted and disengaged from the connecting aperture.

The oscillatable movement of the actuating member 21 allows for advancing or retracting movement of the connection pin 18 and in moving from the advanced position to the retracted position under the influence of the retracting spring 19 the inner end 28 of the connecting pin which initially engages the advancing cam face 24 rides over the common edge 27 and subsequently engages the retracting cam face 26.

The inner end 28 of the connecting pin is preferably flat and engages either the retracting or advancing cam face in face-to-face relationship. As mentioned, the advancing and retracting cam faces are preferably at substantially right angles and the action of the retracting spring 19 urging the connecting pin into engagement with either of these faces ensures that the latch mechanism is positively maintained in either its locked or unlocked condition in a simple and efficient manner.

The actuating member 21 is also provided at its outer end portion with an external cam 29 located adjacent to the inner end portion 31 of the locking barrel.

Associated with the external cam is a cam projector 32 extending from the inner end portion 3-1 of the locking barrel and engageable with an external cam face 33 formed on the external cam.

The arrangement of the cam projection 32 and external cam are such that normally, with the locking barrel 12 in a neutral position ready for insertion or withdrawal of the key 13 from the key-way 34 therein, the cam projection 32 is so positioned as to be incapable of engaging with the external cam due to relative rotational movement of the actuating member 21 and the lockable operating handle 8. However, when the key 13 is inserted in the key-way 34 the locking barrel 12 is capable of oscillatable movement in either direction whereupon the cam projection 32 engages the external cam face 33 and further movement causes the actuating member 21 to oscillate in that corresponding direction. After the locking barrel 12 has been oscillated in one direction to locate the connecting pin 18 in its advanced or retracted position the locking barrel 12 may be returned to its neutral position without fouling the external cam 29 thus enabling withdrawal of the key 13 from the key-way '34 leaving the latch operating mechanism in its locked or unlocked condition. Similarly, the locking barrel 12 may be oscillated in the opposite direction for the reverse procedure.

The outer end portion 36 of the inner coupling member 16 is preferably formed with a substantially cylindrical outer surface so as to facilitate rotational movement within the outer coupling member 14. The inner coupling member 16 preferably incorporates an axial open ended bore 37 extending therethrough, the outer end portion 38 of the axial bore being of substantially circular crosssection and the opposite inner end portion preferably being of substantially square cross-section for the purpose of operatively engaging with the adjacent end portion of the latch operating shaft 7 which is of complementary formation in external cross-section.

The connecting pin 18 preferably extends through an open ended pin bore 39 at right angles to the axial bore 37 and extending between the latter and the outer surface of the inner coupling member 16. The inner end of the pin bore is preferably enlarged to provide an internal annular shoulder 41.

The connecting pin is preferably provided with an enlarged head 42 at its inner end and in the preferred form the retracting spring 19 is of helical formation and held under compression around the connecting pin 18 between the internal shoulder 41 and the pin bore 39 and the enlarged head 42 on the connecting pin 13.

The actuating member 21 which may be composed of nylon or other plastic material includes the main body 22 on which is formed the internal cam and at the outer end portion of which is formed the external cam 29. The main body may also have an enlongated rearwardly extending snib shaft 43 for a purpose hereinafter described.

The advancing and retracting cam faces of the internal cam are both preferably located inwardly of the outer surface 44 of the main body of the actuating member so that the connecting pin in its advanced and retracted positions projects within the outer end portion of the axial bore 37 to engage the internal cam and at the same time functioning to retain the actuating member 21 by limiting unintentional endwise movement thereof relative to said inner coupling member. The size of the pin bore 39 is preferably sufficient to allow the pin 18 together with the spring 19 to be pressed into the pin bore thereby readily allowing axial installation of the actuating member 21 in the axial bore 37.

The external cam face 33 formed on the external cam preferably extends parallel to the axis of oscillation of the actuating member so as to be symmetrical about one plane of symmetry common to the longitudinal axis of oscillation and entirely to one side of another plane common to the longitudinal axis of oscillation. Within these limitations the external cam face preferably incorporates a pair of opposed convex portions of part circular formation extending inwardly from their outer edges towards a separating portion of inverted V-shape in cross-section. The convex portions are preferably substantially longer than the separating portion which is located adjacent to the axis of oscillation of the actuating member. (See FIGURES 2 and 4.)

Associated with the foregoing the actuating member preferably carries a pair of stops 46 inwardly of the external cam face and arcuately spaced. The pair of stops are so located as to be engageable in turn with a stop lug 47 on the outer end of the inner coupling member so as to allow limited oscillatable movement of the actuating member between extreme positions corresponding to engagement of the retracting and advancing cam faces with the inner end of the connecting pin.

Apart from the locking barrel 12 and outer cylinder 11, the lock also preferably includes a web 48 projecting laterally from the outer cylinder and forming a radial extension thereof so as to accommodate the tumbler pins (see FIGURE 1) of the lock. With the preferred arrangement the key-way 34 and web 48 are substantially parallel or coplanar when the locking barrel is in its neutral posi tion ready for insertion or withdrawal of the key 13 into the key-way.

The lock may also include a locating pin 49 mounted in the web 48 but urged by a spring 51 into engagement with the locking barrel 12. Associated with the locating pin 49 is a locating groove in the outer surface of the locking barrel and adapted to register with the locating pin when the key-way is in its neutral position. The locating groove is preferably provided with inclined edges enabling the locating pin to be readily dislodged therefrom and the purpose of the locating pin is to provide a simple indication of when the keyway is in its neutral position ready for withdrawal of the key after a locking or unlocking operation.

As mentioned previously the locking barrel is provided with a cam projection 32 adapted to co-operate with the external cam but in a preferred construction the cam projection is formed by two cam pins 52 provided adjacent the periphery of the locking barrel and located substantially symmetrically about the axis of rotation of the locking barrel and each on one side of the key-way. Each cam pin is preferably of circular shape in cross-section to enable it to readily ride over the associated external cam face.

The outer coupling member 14 may be formed integral with the lockable operating handle 8 and is preferably of bifurcated formation with opposed part tubular sections (see FIGURE 6).

The part tubular sections are separated by opposed elongated slots one of which functions as the connecting aperture 17 thus constituting an elongated connecting slot and the other functions to assist installation of the lock and may therefore be termed an installation slot 53.

The inner end portion of the lock may project into the outer end portion of the outer coupling member with the outside edge portion 54 of the web in line with the connecting slot and the diametrically opposed outside edge portion 56 of the outer cylinder in line with the installation slot 53.

With this arrangement the lock may be installed into the lockable operating handle 8 from the inner end portion through the outer coupling member 14 and into a complementary shaped socket in the lockable operating handle simply by passing the lock through the outer coupling member with the opposed outside edge portions of the web and outer cylinder being embraced by the connecting slot and installation slot respectively as the lock passes through the outer coupling member.

When installed the outer end of the locking barrel and key-way are accessible from the outer end of the lockable operating handle.

The lockable operating handle preferably includes a main body 57 which may be integral with the outer coupling member and a manually operable lever 58 projecting laterally from the main body. The main body 57 houses the lock and it is preferred that the manually operable lever should extend in a direction substantially parallel to the key-way 34 when in its neutral position. Furthermore the web 48 of the lock and the manually operable lever 58 preferably both extend away from the locking barrel in substantially the same direction.

For compact construction the axis of the locking barrel 12 is preferably offset from the axis of the main body 57 on that side remote from the manuallyoperable lever 58. With this arrangement the lock (in the direction of its width) preferably extends across substantially the entire width of said main body 57.

The latch operating mechanism of the invention may also be associated with a free operating handle 58 connectable to that end of the latch operating shaft 7 remote from the lockable operating handle 8. With this arrangement the latch operating shaft 7 preferably includes an open ended bore extending therethrough and rotatably accommodating the aforesaid snib shaft 43 which extends rearwardly of the actuating member.

The free operating handle 58 houses a snib 59 coupled to the snib shaft and projecting through a snib aperture in the free operating handle so as to be readily accessible from the exterior thereof.

It will be appreciated that with the preferred arrangement as described the snib 59 is oscillatable to operate the actuating member 21 independently of operation of the lock in order to enable locking and unlocking of the latch mechanism from that side adjacent to the free operating handle.

In use, the latch operating mechanism as described in its preferred construction may be installed together with a door latch 6 on an external door of a dwelling or the like with the lockable operating handle 8 on the outside. The arrangement is such that with the connecting pin 18 engaged in the connecting slot the door latch may be immediately operated from either side of the door simply by use of the lockable or free operating handles.

However, the door may effectively be locked from entry from outside either by actuating the snib 59 or using the key 13 in the key-way to move the actuating member so as to retract the connecting pin 18 from the connecting slot. In this position the lockable operating handle 8 is disconnected from the latch operating shaft 7 and therefore cannot be used to open the door. Thus the door may only be opened from the outside after transferring the latch mechanism to its unlocked condition by using the key or by operation of the snib from inside the door. The door is always openable from the interior by using the free operating handle.

Preferably a yieldable retaining means is employed to positively urge the lockable operating handle to a position in line with the key-way even when the latch mechanism is in its unlocked condition. A spring 61 or other means may be used for this purpose.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A latch operating mechanism for a door latch having a laterally projecting latch operating shaft oscillatable about its longitudinal axis to actuate said latch, said operating mechanism including: a lockable operating handle; a lock incorporated in said lockable operating handle and having an outer cylinder, a locking barrel rotatably housed in said outer cylinder and a keyway formed in said locking barrel to receive a key for operating said locking barrel; an outer hollow coupling member fixed to the lockable operating handle and rotatable therewith; an inner coupling member axially connectable to the latch operating shaft for rotation therewith and mounted for axial rotation in the outer coupling member; a connecting aperture formed in the outer coupling member; a con necting pin located in the inner coupling member and engageable with the connecting aperture when advanced to effect connection between the coupling members but disengaged from said connecting aperture when retracted; a retracting spring urging said connecting pin towards its retracted position; actuating means operable by oscillation of the locking barrel to advance or retract the connecting pin into and out of engagement with said connecting aperture to effect unlocking and locking of said latch mechanism respectively; characterised in that said actuating means includes: an actuating member oscillatably mounted in the inner coupling member, said actuating member having a main body within the inner coupling member, an internal cam formed on said main body, said internal cam being provided with an advancing cam face and a retracting cam face, said connecting pin having an inner end which engages the internal cam so that when the inner end engages the advancing cam face the connecting pin is advanced and when the inner end engages the retracting cam face the connecting pin is retracted, said actuating member having an outer end portion on that end nearer said lockable operating handle, said locking barrel having an inner end portion located adjacent said outer end portion, an external cam with an external cam face formed on said outer end portion, a cam projection extending from said inner end portion, the relative arrangement of said cam projection and said external cam face being such that when the key-way is in a neutral position ready for insertion or withdrawal of said key the cam projection is incapable of engaging said external cam face during any relative rotational movement of said actuating member and said lockable operating handle whereas the key may be used to oscillate said locking barrel in either direction from said neutral position so that said cam projection oscillatably engages said external cam face whereby said latch mechanism may be locked by turning the locking barrel in one direction from its neutral position and unlocked by turning the locking barrel in the other direction from its neutral position.

2. A latch operating mechanism as claimed in claim 1 further characterised in that said external cam face extends substantially parallel to the axis of oscillation of said actuating member, is symmetrical about one plane of symmetry common to said axis of oscillation, and is located entirely to one side of another plane common to said axis of oscillation, said external cam face incorporating a pair of opposed convex portions of part circular formation extending inwardly from their outer edges towards a separating portion of inverted V-shape in crosssection, the convex portions being substantially longer than the separating portion which is located adjacent to said axis of oscillation, said cam projection consisting of two cam pins of substantially circular shape in crosssection located adjacent the periphery of said locking barrel and substantially symmetrically about the axis of rotation of the locking barrel and each on one side of said keyway.

3. A latch operating mechanism as claimed in claim 2 further characterised in that the advancing and retracting cam faces are at substantially right angles to each other and merge at a common edge, the inner end of the connecting pin being flat and engageable in face-to-face relationship with each of said advancing and retracting cam faces and in moving from the advanced tothe retracted positions and vice-versa the inner end of said connecting pin rides over said common edge.

4. A latch operating mechanism as claimed in claim 3 further characterised in that said lockable operating handle includes a main body and a manually operable lever projecting laterally from the main body, said lock including a web projecting laterally from said outer cylinder and forming a radial extension thereof substantially parallel to the key-way when in its neutral position, said web accommodating tumbler pins of said lock, said main body housing said lock with the manually operable lever extending in a direction substantially parallel to the keyway when in its neutral position, the web of the lock and the manually operable lever extending away from the locking barrel in substantially the same direction, and the axis of the locking barrel being offset sidewardly from the axis of the main body on that side remote from the manually operable lever, so that in the direction of its width the lock extends across substantially the entire width of said main body.

5. A latch mechanism as claimed in claim 4 further characterised in that it includes a free operating handle connectable to said latch operating shaft at that end remote from said lockable operating handle for oscillation of said latch operating shaft, a snib shaft connected to said actuating member and extending rearwardly therefrom in a direction away from said lockable operating handle to pass through and be rotatably accommodated in a longitudinally extending open ended bore formed in said latch operating shaft, a snib aperture formed in said free operating handle, a snib located in said snib aperture and connected to said snib shaft, said snib being freely accessible from the exterior of said free operating handle, whereby said latch mechanism may be locked and unlocked by manually oscillating said actuating member through said snib.

6. A latch mechanism as claimed in claim 5 further characterised in that the inner coupling member incorporates an axial open-ended bore extending therethrough and accommodating the main body of said actuating member, a pin bore for accommodating said connecting pin extending at right angles to said last mentioned axial bore between the latter and. the outer surface of said inner coupling member, the inner end of said pin bore being enlarged to provide an internal annular shoulder, said connecting pin having an enlarged head at its inner end, Said retracting spring being of helical formation and held under compression between the internal annular shoulder and said enlarged head, the size of said pin bore being sufficient to enable said connecting pin and retracting spring to be pressed into the pin bore to allow axial installation and removal of said actuating member in said inner coupling member.

7. A latch mechanism as claimed in claim 6 further characterised in that said advancing and retracting cam faces are both located inwardly of the outer surface of the main body of the actuating member So that in its operative positions said connecting pin projects within the axial bore of said inner coupling member thus serving to limit unintentional endwise movement of said actuating member relative to said coupling member.

8. A latch mechanism as claimed in claim 7 further characterised in that the actuating member carries a pair of stops inwardly of the external cam face and arcuately spaced, said inner coupling member having a stop lug on its outer end engageable with said pair of stops in turn so as to limit oscillatable movement of the actuating member between extreme positions corresponding to engagement of the retracting and advancing cam faces with the inner end of the connecting pin.

9. A latch mechanism as claimed in claim 8 further characterised in that said lock includes a locating pin urged by a spring into engagement with the locking barre], and a locating groove formed in the outer surface of the locking barrel, the locating pin registering with said locating groove when the key-Way is in its neutral position, the arrangement of the locating pin and locating groove being such that when the locking barrel is rotated the locating pin readily dislodges from the locating groove but returns thereto when the locking barrel is rotated to return the key-way to its neutral position thus providing an indication of when the key-way is returned to its neutral position.

10. A latch mechanism as claimed in claim 9 further characterised in that said connecting aperture is in the form of an elongated slot.

References Cited UNITED STATES PATENTS 649,706 5/1900 Phelps 292-359 2,839,913 11/1956 Friedman et al. l46 3,269,158 5/1964 Andre 70216 MARVIN A. CHAMPION, Primary Examiner.

ROBERT L. WOLFE, Assistant Examiner, 

